The most interesting content, is that which we probably can't safely post in the open.
An underground section of the site, where we'd be able to post in true anonymity, would unlock many doors; giving way to extremely useful content.
A while ago, I had a flash drive totally dedicated to anonymous browsing. I wasn't entirely sure whether it worked effectively, but I'm sure if we plugged our minds together, we could have a dedicated guide to keeping anonymous, and could use that to stay safe when posting fringe content.
Tor would be the ideal place to host such a site imo, as it provides better performance than other competitors such as Freenet. Additionally, word of a Totse on the Tor network would definitely attract some of the Tor browsers who linger on the network; some of whom are probably interesting people with thigns to contribute.
Furthermore, Totse's presence on Tor would mean the network as a whole could benefit in performance and effectiveness as more people are providing their connections.